Charter schools have become an important aspect of Utah's unique K-12 education system as they have increased in both popularity and number in recent years. The increase of charter schools has allowed for a higher degree of parental choice regarding their children's education as well as various effects on the traditional public schools. Economic theory suggests that increased competition may influence firms to increase quality and/or decrease price. The question remains if the same holds for the education market in Utah. Nationwide existing evidence in the literature is mixed, where many studies have shown positive competitive effects of charters on public schools while a few others have shown negative or negligible competitive effects. Further analysis for the Utah education market is therefore warranted. This research identifies and analyzes the competitive effects of charter schools on the academic achievement of students in traditional public schools (K-6) in Utah. School-level criterionreferenced test (CRT) scores serve as a measure of academic achievement for the years 2005 through 2010. For completeness, two broadly-accepted measures of competition are utilized. Results suggest positive and significant competitive effects on traditional public school achievement in the subjects of Language Arts and Science, and negative but mostly not significant effects on Mathematics.